旋流燃烧器给粉方式对锅炉NO排放特性影响的数值模拟  

NO Distribution Numerical Simulation on Different Way of Fuel Feeding for Swirl Combustion Boiler

作　　者：刘建全[1] 孙保民[1] 陈晓萌[1] 孟顺[2] 邵兴兰[2] 李学彦[1] 

机构地区：[1]华北电力大学电站设备状态检测与控制教育部重点实验室,北京102206 [2]哈尔滨工业大学燃烧工程研究所,哈尔滨150001

出　　处：《机械工程学报》2011年第10期119-125,共7页Journal of Mechanical Engineering

摘　　要：使用可实现realizable k-ε双方程模型,对600 MW超临界锅炉LNASB燃烧器燃烧过程进行数值模拟。研究燃烧器给粉方式、二次风量及过量空气系数对炉膛内部NO分布的影响,对燃烧器拟改进结构与原结构NO生成特性进行比较。数值模拟结果表明,内二次风对NO影响较大,内二次风关闭时炉膛出口NO下降22%。主燃烧器区域过量空气系数对NO影响明显,过量空气系数较小时NO生成量较少;中心给粉可以有效地降低锅炉NO的生成,100%负荷投入5层燃烧器时NO下降16%,数值计算结果为燃烧器改进提供了NO生成的理论依据。并与试验结果进行对比,获得比较一致的结果。通过设备改进和燃烧调整,有效地控制了锅炉NO的排放,为LNASB燃烧器设计和运行提供了一定的降低NO的理论基础。The combustion process of LNASB burner is numerically studied in a 600 MW supercritical boiler with realizable k-ε model.The effect of fuel feeding on the burner,NO distribution inside the furnace on different secondary air flow and excess air ratio are researched,the characteristics of NO formation of the burners with the improved structure and the original structure are compared.Numerical simulation results show that the inner secondary air has great influence on NO,when the inner secondary air is shut down,NO at furnace outlet decreases 22%.The excess air ratio of the main burner region has significant influence on the NO formation,when the excess air ratio is small,there is less NO formation in the boiler.Central fuel feeding can effectively reduce NO formation.With full load input into five-layer burners,NO will be reduced by 16%,the result of numerical calculation can provide the theoretical basis for the formation of NO,and it agrees with the experimental result.Through equipment improvement and combustion adjustment,the boiler NO emission can be effectively controlled,thus providing a theoretical basis of reducing NO for LNASB burner design and operation.

关 键 词：中心给粉 LNASB燃烧器 数值模拟 Realizable k-ε模型 

分 类 号：TK22[动力工程及工程热物理—动力机械及工程]